1. Technical Field
The present invention relates generally to door systems, and more particularly to automatic door safety systems for detecting hazard conditions and operating accordingly.
2. Background of the Invention
Automatic doors and door systems are becoming increasingly popular in both commercial and residential settings. Such door systems typically comprise the door and a motor which opens and closes the door when a switch is activated. In addition, the systems often include additional devices and features which contribute to the utility of the systems. For example, home garage doors or warehouse access doors often have transmitter and receiver buttons which allow the doors to be opened remotely. Other door systems may have sensors which automatically close or open doors for safety reasons. For example, in case of a fire, a sensor may cause a fire-resistant door to close, cutting off the air supply to a fire or preventing the fire from spreading to other areas.
Conventional systems are not, however, without drawbacks. For example, as the doors close, many existing systems do not provide adequate mechanisms for causing the door to react should an object obstruct the path of the door. For example, when a car or an animal moves into the door's path, the door systems do not sense these conditions, and the door continues to close, causing damage or injury.
In attempts to prevent injury or damage, some door systems may have safety devices which cause the door to stop when the door contacts an obstruction. For example, some door systems may have resistance sensors which stop the motor if the door encounters resistance before reaching a predetermined point, for example, the floor. Such safety devices, however, are less than ideal. Generally, these devices only stop the door after the door contacts the obstruction. In some cases this may be too late to prevent damage. For example, if a door comes down on a vehicle, damage may have already been done. The paint may be scratched and, if the door is not stopped soon enough, the downward pressure of the door may dent the hood. Similarly, the downward force could injure animals or people.
Further, if safety measures are included to detect obstructions and other hazards, the safety measures are, like any electromechanical system, subject to potential failures. To prevent damage or injury, the safety devices should be operating properly to identify potential problems and take the appropriate action. For example, if a hazard sensing device is not functioning properly, the door continues to close, regardless of whether an obstruction is encountered, potentially causing damage or injury.